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#include "fpi.h"
/*
* the following routines depend on memory format, not the machine
*/
void
fpis2i(Internal *i, void *v)
{
Single *s = v;
i->s = (*s & 0x80000000) ? 1: 0;
if((*s & ~0x80000000) == 0){
SetZero(i);
return;
}
i->e = ((*s>>23) & 0x00FF) - SingleExpBias + ExpBias;
i->h = (*s & 0x007FFFFF)<<(1+NGuardBits);
i->l = 0;
if(i->e)
i->h |= HiddenBit;
else
i->e++;
}
void
fpid2i(Internal *i, void *v)
{
Double *d = v;
i->s = (d->h & 0x80000000) ? 1: 0;
i->e = (d->h>>20) & 0x07FF;
i->h = ((d->h & 0x000FFFFF)<<(4+NGuardBits))|((d->l>>25) & 0x7F);
i->l = (d->l & 0x01FFFFFF)<<NGuardBits;
if(i->e)
i->h |= HiddenBit;
else
i->e++;
}
void
fpiw2i(Internal *i, void *v)
{
Word w, word = *(Word*)v;
short e;
if(word < 0){
i->s = 1;
word = -word;
}
else
i->s = 0;
if(word == 0){
SetZero(i);
return;
}
if(word > 0){
for (e = 0, w = word; w; w >>= 1, e++)
;
} else
e = 32;
if(e > FractBits){
i->h = word>>(e - FractBits);
i->l = (word & ((1<<(e - FractBits)) - 1))<<(2*FractBits - e);
}
else {
i->h = word<<(FractBits - e);
i->l = 0;
}
i->e = (e - 1) + ExpBias;
}
void
fpii2s(void *v, Internal *i)
{
short e;
Single *s = (Single*)v;
fpiround(i);
if(i->h & HiddenBit)
i->h &= ~HiddenBit;
else
i->e--;
*s = i->s ? 0x80000000: 0;
e = i->e;
if(e < ExpBias){
if(e <= (ExpBias - SingleExpBias))
return;
e = SingleExpBias - (ExpBias - e);
}
else if(e >= (ExpBias + (SingleExpMax-SingleExpBias))){
*s |= SingleExpMax<<23;
return;
}
else
e = SingleExpBias + (e - ExpBias);
*s |= (e<<23)|(i->h>>(1+NGuardBits));
}
void
fpii2d(void *v, Internal *i)
{
Double *d = (Double*)v;
fpiround(i);
if(i->h & HiddenBit)
i->h &= ~HiddenBit;
else
i->e--;
i->l = ((i->h & GuardMask)<<25)|(i->l>>NGuardBits);
i->h >>= NGuardBits;
d->h = i->s ? 0x80000000: 0;
d->h |= (i->e<<20)|((i->h & 0x00FFFFFF)>>4);
d->l = (i->h<<28)|i->l;
}
void
fpii2w(Word *word, Internal *i)
{
Word w;
short e;
fpiround(i);
e = (i->e - ExpBias) + 1;
if(e <= 0)
w = 0;
else if(e > 31)
w = 0x7FFFFFFF;
else if(e > FractBits)
w = (i->h<<(e - FractBits))|(i->l>>(2*FractBits - e));
else
w = i->h>>(FractBits-e);
if(i->s)
w = -w;
*word = w;
}
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